In advanced modern turbines, the temperature of the turbine & apos; s first blade row which is called the turbine & apos; s hot part, increases almost as 1000?. These blades must operate for long periods of time. Since, the main failure reason of the parts operating under high temperature and cyclic loading conditions is fatigue as well as creeping phenomena, acquiring an accurate estimate of these blades & apos; lifetime under creeping and fatigue interactions is very necessary for theoretical and practical requirements. The fatigue of the first blade row of the micro turbine TRI60 is analyzed in this study. For the purpose of estimating the fatigue lifetime of turbine and motor, heat transfer of blades as well as thermal stress is analyzed at first via ABAQUS software. Consequently, a fatigue analysis under full cycle and within the interval of 2/3 v_max to v_max is performed using Smith-Watson-Taper algorithm and transient modal analysis via Fe-safe software.

Chemically attachment of Schiff base complexes on multiwalled carbon nanotubes (MWCNTs) surfaces through a convenient and simple method was studied. In the first step of this method, we present a new method for preparation of aminated MWCNTs in order to attachment of (new) chlorinated salen Schiff bases. Amination of multiwalled carbon nanotubes performed under microwave (MW) irradiation through a one pot two step reaction. The chemically attachment of salen Schiff bases on functionalized MWCNTs (salen@MWCNTs) performed under a facile simple nucleophilic substitution reaction and complexation of attached salen Schiff bases (salen complex@MWCNTs) in last step, have been occurred with reaction of transition metal salts and salen@MWCNTs. The obtained products were characterized in detail, using FTIR, XRD, UV-Vis absorption, SEM and EDX methods.

This study examines the properties of the downward-sloping region of the linear supply function equilibrium (cartel case), which has not been considered in the literature. In simple duopoly set-tings, we find two regions, depending on the cartel type. Specifically, in a tight cartel, fiercer competition yields higher profits to firms, but the equilibrium is unstable. Instead, in the case of a loose cartel, fiercer competition yields lower profits, and the equilibrium is stable. Thus, in our framework, individual firms’ profits as a stable equilibrium are maximized not in a pure cartel, but rather in a somewhat weak cartel. This result sheds lights on the situations policymakers should focus on while monitoring cartels.

Sustainability in project operations such as financial, social and environmental sustainability is one of the most prominent issues of the present times to address. The increased focus on sus-tainable business operations has changed the viewpoint of researchers and corporate community towards the project management. Today sustainability in business operations along with sustain-ability of natural and environmental resources are of paramount significance which has further caused a huge impact on conception, planning, scheduling and execution of the project manage-ment activities. In this paper, a literature review between 1987 and 2018 on different issues af-fecting the sustainability in project management is carried out. The present study also identifies and discusses the future possibilities to apply computational procedures in order to estimate and optimize the sustainability issues in the management of projects, for example the computational evolutionary algorithms can be applied to formulate the multi-objective decision-making problem after considering critical factors of sustainability in the projects and then yielding optimized solu-tions for the formulated problem to achieve sustainability in the projects. A new integrated framework with the inclusion of feedback function for assessment of each decision and actions taken towards the sustainability of the projects is also identified and presented.

There are literally several studies accomplished to predict the fatigue life of leaf springs but estimation of fatigue life of a parabolic leaf spring by using CAE tools has not yet been executed in the past. Parabolic spring is an important component in a vehicle suspension system. It needs to have excellent fatigue life and in today’s scenario manufacturers rely on constant loading fatigue analysis. The objective of this work is to perform the fatigue analysis of parabolic leaf spring by three different methods where CAE analysis is performed to observe the distribution of stress fatigue life and damage using Goodman approach. In this work, fatigue life of the parabolic leaf spring is determined as per SAE spring design manual and experimentally by testing on full scale fatigue testing machine. ANSYS is used for CAE solution for the prediction of leaf springs fatigue life considering stress theory. The fatigue life estimated by all three modes is then compared for the purpose of validation. The methodology used in this paper brings a practical approach to the professionals in the industries who are engaged for design of mechanical components.

The present paper deals with the characterization of ion exchange resins Dowex 550A LC and Indion-930A based on kinetics of ion-isotopic exchange reactions for which the short lived radioactive isotopes 131I and 82Br were used as a tracers. The study was performed for different concentration of ionic solution varying from 0.001 mol/L to 0.004 mol/L and temperature in the range of 30.0 °C to 45.0 °C. The results indicate that as compared to bromide ion-isotopic exchange reaction, iodide exchange reaction take place at the faster rate. For both the ion-isotopic exchange reactions, under identical experimental conditions, the values of specific reaction rate increases with increase in the ionic concentration and decreases with rise in temperature. It was observed that at 35.00C, 1.000 g of ion exchange resins and 0.002 mol/L labeled iodide ion solution for iodide ion-isotopic exchange reaction, the values of specific reaction rate (min-1), amount of ion exchanged (mmol), initial rate of ion exchange (mmol/min) and log Kd were 0.270, 0.342, 0.092 and 11.8 respectively for Dowex 550A LC resin, which was higher than the respective values of 0.156, 0.241, 0.038 and 7.4 as that obtained for Indion-930A resins. From the results, it appears that Dowex 550A LC resins show superior performance over Indion-930A resins under identical experimental conditions.

Social media has grown very quickly and has affected all dimensions of the world’s community. The purpose of this article is to review valid articles on the relationship between social media and promotion using manual and bibliometrics analysis methods and identify top themes in these articles. We review the papers published between 2007 and the first month of 2019 in Scopus. 1,840 articles were published in the mentioned period. In this article, we review various charts including word dynamics, the contributions of different countries, country scientific production, corresponding author's country, the frequency distribution of sources, collaboration network and country collaboration map. The study indicates that Canada, Australia and France were the most productive countries in this area.

A growing number of companies treat "sustainability" as an important objective in their strategy. Sustainable and green suppliers increase efficiency by reducing costs and waste in industries. Sustainable and green supplier selection is a critically important factor in moving forward along the path of sustainability. A fuzzy R-method is proposed in this paper based on ranking the fuzzy numbers of alternative suppliers and criteria. Triangular fuzzy membership function and different fuzzy scales are presented to demonstrate and validate the proposed method. Fuzzy composite scores are generated, and these scores are converted into crisp forms to evaluate the alternative suppliers. The novelty of the proposed method is that it is simple, can deal with qualitative and quantitative criteria of supplier selection, and requires less computational effort for evaluating and ranking the green and sustainable suppliers in fuzzy group decision-making situations. The weights of the criteria and alternative suppliers are generated using a simple equation and hence there is no need to apply different methods for weights generation and ranking. Furthermore, this method does not require normalization of the data. Two realistic group decision-making problems of green and sustainable supplier selection to test the method. Sensitivity analysis for the proposed method is also conducted to check the consistency of the proposed method to different weights of the criteria. The proposed method is effective, robust, and competitive to the existing multi-criteria decision making (MCDM) methods of sustainable supplier selection.

This paper presents the free vibration analysis of stiffened isotropic plate by means of finite element method. Stiffeners are used in plates to increase the strength and stiffness. The effect of position of stiffeners on isotropic plate has been studied which involve the possible combination of clamped and free edge condition. The model has been discretized using a 20-node solid element (SOLID186) from the ANSYS element library. The natural frequencies are calculated using Block-Lanczos algorithm. The comparisons of stiffened plate with the available results are found to be in good uniformity. The effect of different boundary conditions, stiffeners location, thickness ratio, stiffener thickness to plate thickness and aspect ratio on the vibration analysis of stiffened plates has been studied.

New silica-supported yttrium trinitrate was prepared, characterized, and used as a reusable catalyst for the three-component synthesis of quinazolinones/thiones via the Biginelli condensation under solvent-free conditions. Non-toxic reagent, short reaction times, simple work-up procedure, and high yield of the products are some of the important advantages of present method.